This prospective study investigated the role of whole-brain CT perfusion (CTP) studies in the identification of patients at risk for delayed ischemic neurological deficits (DIND) and of tissue at risk for delayed cerebral infarction (DCI).

Methods: Forty-three patients with aneurysmal subarachnoid hemorrhage (aSAH) were included in this study. A CTP study was routinely performed in the early phase (Day 3). The CTP study was repeated in cases of transcranial Doppler sonography (TCD)–measured blood flow velocity (BFV) increase of > 50 cm/sec within 24 hours and/or on Day 7 in patients who were intubated/sedated.

Results: Early CTP studies revealed perfusion deficits in 14 patients, of whom 10 patients (72%) developed DIND, and 6 of these 10 patients (60%) had DCI. Three of the 14 patients (21%) with early perfusion deficits developed DCI without having had DIND, and the remaining patient (7%) had neither DIND nor DCI. There was a statistically significant correlation between early perfusion deficits and occurrence of DIND and DCI (p < 0.0001). A repeated CTP was performed in 8 patients with a TCD–measured BFV increase > 50 cm/sec within 24 hours, revealing a perfusion deficit in 3 of them (38%). Two of the 3 patients (67%) developed DCI without preceding DIND and 1 patient (33%) had DIND without DCI. In 4 of the 7 patients (57%) who were sedated and/or comatose, additional CTP studies on Day 7 showed perfusion deficits. All 4 patients developed DCI.

Conclusions: Whole-brain CTP on Day 3 after aSAH allows early and reliable identification of patients at risk for DIND and tissue at risk for DCI. Additional CTP investigations, guided by TCD–measured BFV increase or persisting coma, do not contribute to information gain.